Renal denervation is a method whereby sympathetic nerve activity involving the targeted kidney is blocked or suppressed. Excessive sympathetic activity has been implicated in vasoconstriction, reduction in renal blood flow, retention of fluid and salt, elevated renin generation, over-activation of the renin-angiotension-aldosterone mechanism, increased catecholamine production and, ultimately, arterial hypertension. Thus, renal denervation is used to alter neural signaling mechanisms involving the kidney to treat hypertension and other related disorders.
Renal denervation is achieved through destruction of afferent and efferent nerve fibers that run adjacent to the renal arteries. Successful renal denervation results in lower systemic arterial blood pressure in a treated patient. Renal denervation has also been shown to have benefits in conjunction with current guideline-based treatment strategies in heart failure, diabetes, obesity, sleep apnea, and ventricular tachycardia (VT). A conventional renal denervation procedure involves introducing a radiofrequency (RF) ablation catheter, which ablates renal nerves at various locations using variable energy. Ideally, the operator's objective is to ablate as minimally as necessary to achieve an appropriate degree of renal denervation for the least amount of time and at the fewest locations. In order to achieve it, there is a need for feedback mechanisms to provide the operator with insight about the efficacy of the renal denervation treatment during the treatment procedure. This feedback would enable the operator to decide whether additional power, duration, and/or ablation locations are needed to accomplish adequate renal denervation.